Legalizer: Reword comment again, per Duncan's suggestion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173625 91177308-0d34-0410-b5e6-96231b3b80d8
Start using more of the AttrNode in the AttributeSetImpl class.

Also add some asserts.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173627 91177308-0d34-0410-b5e6-96231b3b80d8
s/AttrList/pImpl/g in AttributeSet. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173628 91177308-0d34-0410-b5e6-96231b3b80d8
[XCore] Add missing l2r instructions.

These instructions are not targeted by the compiler but they are
needed for the MC layer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173629 91177308-0d34-0410-b5e6-96231b3b80d8
Add some helpful comments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173631 91177308-0d34-0410-b5e6-96231b3b80d8
Privitize some the copy c'tor and assignment operator of uniquified objects.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173632 91177308-0d34-0410-b5e6-96231b3b80d8